This just inserts some infrastructure in preparation for handling
other types of ceph message data items. No functional changes,
just trying to simplify review by separating out some noise.
I will fold this into the previous patch before committing.
Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
---
include/linux/ceph/messenger.h | 8 +++-
net/ceph/messenger.c | 99
++++++++++++++++++++++++++++++++--------
2 files changed, 85 insertions(+), 22 deletions(-)
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index 1486243..716c3fd 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -97,8 +97,12 @@ static __inline__ bool ceph_msg_data_type_valid(enum
ceph_msg_data_type type)
struct ceph_msg_data_cursor {
bool last_piece; /* now at last piece of data item */
- struct page *page; /* current page in pagelist */
- size_t offset; /* pagelist bytes consumed */
+ union {
+ struct { /* pagelist */
+ struct page *page; /* page from list */
+ size_t offset; /* bytes from list */
+ };
+ };
};
struct ceph_msg_data {
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index b978cf8..ce81164 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -742,21 +742,16 @@ static void iter_bio_next(struct bio **bio_iter,
unsigned int *seg)
#endif
/*
- * Message data is handled (sent or received) in pieces, where each
- * piece resides on a single page. The network layer might not
- * consume an entire piece at once. A data item's cursor keeps
- * track of which piece is next to process and how much remains to
- * be processed in that piece. It also tracks whether the current
- * piece is the last one in the data item.
+ * For a pagelist, a piece is whatever remains to be consumed in the
+ * first page in the list, or the front of the next page.
*/
-static void ceph_msg_data_cursor_init(struct ceph_msg_data *data)
+static void ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data *data)
{
struct ceph_msg_data_cursor *cursor = &data->cursor;
struct ceph_pagelist *pagelist;
struct page *page;
- if (data->type != CEPH_MSG_DATA_PAGELIST)
- return;
+ BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
pagelist = data->pagelist;
BUG_ON(!pagelist);
@@ -771,12 +766,7 @@ static void ceph_msg_data_cursor_init(struct
ceph_msg_data *data)
cursor->last_piece = pagelist->length <= PAGE_SIZE;
}
-/*
- * Return the page containing the next piece to process for a given
- * data item, and supply the page offset and length of that piece.
- * Indicate whether this is the last piece in this data item.
- */
-static struct page *ceph_msg_data_next(struct ceph_msg_data *data,
+static struct page *ceph_msg_data_pagelist_next(struct ceph_msg_data *data,
size_t *page_offset,
size_t *length,
bool *last_piece)
@@ -808,11 +798,8 @@ static struct page *ceph_msg_data_next(struct
ceph_msg_data *data,
return data->cursor.page;
}
-/*
- * Returns true if the result moves the cursor on to the next piece
- * (the next page) of the pagelist.
- */
-static bool ceph_msg_data_advance(struct ceph_msg_data *data, size_t bytes)
+static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data *data,
+ size_t bytes)
{
struct ceph_msg_data_cursor *cursor = &data->cursor;
struct ceph_pagelist *pagelist;
@@ -844,6 +831,78 @@ static bool ceph_msg_data_advance(struct
ceph_msg_data *data, size_t bytes)
return true;
}
+/*
+ * Message data is handled (sent or received) in pieces, where each
+ * piece resides on a single page. The network layer might not
+ * consume an entire piece at once. A data item's cursor keeps
+ * track of which piece is next to process and how much remains to
+ * be processed in that piece. It also tracks whether the current
+ * piece is the last one in the data item.
+ */
+static void ceph_msg_data_cursor_init(struct ceph_msg_data *data)
+{
+ switch (data->type) {
+ case CEPH_MSG_DATA_NONE:
+ case CEPH_MSG_DATA_PAGES:
+ break;
+ case CEPH_MSG_DATA_PAGELIST:
+ ceph_msg_data_pagelist_cursor_init(data);
+ break;
+#ifdef CONFIG_BLOCK
+ case CEPH_MSG_DATA_BIO:
+#endif /* CONFIG_BLOCK */
+ default:
+ break;
+ }
+}
+
+/*
+ * Return the page containing the next piece to process for a given
+ * data item, and supply the page offset and length of that piece.
+ * Indicate whether this is the last piece in this data item.
+ */
+static struct page *ceph_msg_data_next(struct ceph_msg_data *data,
+ size_t *page_offset,
+ size_t *length,
+ bool *last_piece)
+{
+ switch (data->type) {
+ case CEPH_MSG_DATA_NONE:
+ case CEPH_MSG_DATA_PAGES:
+ break;
+ case CEPH_MSG_DATA_PAGELIST:
+ return ceph_msg_data_pagelist_next(data, page_offset, length,
+ last_piece);
+#ifdef CONFIG_BLOCK
+ case CEPH_MSG_DATA_BIO:
+ break;
+#endif /* CONFIG_BLOCK */
+ }
+ BUG();
+ return NULL;
+}
+
+/*
+ * Returns true if the result moves the cursor on to the next piece
+ * of the data item.
+ */
+static bool ceph_msg_data_advance(struct ceph_msg_data *data, size_t bytes)
+{
+ switch (data->type) {
+ case CEPH_MSG_DATA_NONE:
+ case CEPH_MSG_DATA_PAGES:
+ break;
+ case CEPH_MSG_DATA_PAGELIST:
+ return ceph_msg_data_pagelist_advance(data, bytes);
+#ifdef CONFIG_BLOCK
+ case CEPH_MSG_DATA_BIO:
+ break;
+#endif /* CONFIG_BLOCK */
+ }
+ BUG();
+ return false;
+}
+
static void prepare_message_data(struct ceph_msg *msg,
struct ceph_msg_pos *msg_pos)
{
--
1.7.9.5
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